Numerous types of dispensers for flexible sheet material wound on cores, such as rolls of paper towels, are known in the prior art. The core on which the flexible sheet material is wound typically has supporting spindles or protrusions extending beyond the ends of the rolls. The spindles are used to support the roll in, and guide it through, the dispenser. These dispensers can basically be classified into two groups. Dispensers in the first group are sized to contain a single roll of flexible sheet material and dispense flexible sheet material from the roll. Dispensers in the second group are sized to contain a plurality of rolls of flexible sheet material, dispense flexible sheet material from a roll in a dispensing position, and automatically transfer a roll from a reserve position to a dispensing position.
The first group of dispensers, i.e., single roll dispensers, are conveniently sized to fit into many institutional or public restrooms. However, because they only contain a single roll at a given time, maintenance personnel are forced to either: (a) replace partially used rolls, or (b) wait until the rolls are entirely depleted which typically leaves users without paper towels. Thus, if maintenance personnel replace partially used rolls, the dispensers are deficient because they increase waste and roll supply costs. Alternatively, if maintenance personnel elect not to replace the rolls until the rolls are fully or substantially depleted, the dispensers are deficient because they leave users without paper towels. Further, these dispensers require a high maintenance cost due to the high frequency of inspection inherent in single roll dispensers.
The second group of dispensers, i.e., the multiple roll dispensers, overcome many of the aforementioned problems associated with the first group of dispensers. However, they require additional mounting space because they can be two or more times the size of the single roll dispensers. This results in dispensers that may be difficult and/or undesirable to mount conveniently in public or institutional restrooms due to their size.
U.S. Pat. No. 4,944,466 to Jespersen, which is incorporated herein by reference, discloses a dispenser which falls into the second group. The dispenser includes an automatic roll transferring system having side tracks, a holding lever, a retaining plate, and a spring biased sensing plate. The holding lever has a lower projection for holding a dispensing roll in a dispensing position and an upper projection for holding a reserve roll in a reserve position. When the diameter of the dispensing roll is greater than a predetermined diameter, the sensing plate is in a first position, which in turn, keeps the retaining plate in a position to lock the holding lever. Once the dispensing roll is depleted to a size less than the predetermined diameter, the sensing plate moves under its spring biasing to move the retaining plate unlocking the holding lever. When holding lever is unlocked, the weight of the reserve roll causes holding lever to rotate and the reserve roll falls down the guide tracks into the dispensing position. The continued dispensing of the substantially depleted roll automatically initiates the feeding of the sheet material from the recently dropped reserve roll. When the dispensing roll is in a dispensing position, it is either (i) supported by its core or (ii) supported initially by a supporting roller and later supported by its core. However, as previously described, the dispenser contains two full rolls and is significantly larger than a single roll dispenser, and thus, it may be difficult and/or undesirable to mount conveniently in certain public and institutional restrooms.
Therefore, a dispenser was thus needed which would overcome the problems of leaving users without paper towels and the high maintenance and material costs associated with single roll dispensers, and which would also overcome the size and mounting limitations associated with the larger multiple roll dispensers. The present invention was developed to accomplish this objective.